<?php

/**
 * 分页类，以组件形式存在于componnets文件中
 * 类名要和文件名一致
 */
class Pagination
{
    private $total; //数据表中总记录数
    private $listRows; //每页显示行数
    private $limit;
    private $uri;
    private $pageNum; //页数
    private $config = array('header' => "个记录", "prev" => "上一页", "next" => "下一页", "first" => "&laquo;", "last" => "&raquo;");
    private $listNum = 8;

    /*
     * $total
     * $listRows
     */
    public function __construct($total, $listRows = 10, $pa = "")
    {
        $this->total = $total;
        $this->listRows = $listRows;
        $this->uri = $this->getUri($pa);
        $this->page = !empty($_GET["page"]) ? $_GET["page"] : 1;
        $this->pageNum = ceil($this->total / $this->listRows);
        $this->limit = $this->setLimit();
    }

    private function setLimit()
    {
        return "Limit " . ($this->page - 1) * $this->listRows . ", {$this->listRows}";
    }

    private function getUri($pa)
    {
        $url = $_SERVER["REQUEST_URI"] . (strpos($_SERVER["REQUEST_URI"], '?') ? '' : "?") . $pa;
        $parse = parse_url($url);
        if (isset($parse["query"])) {
            parse_str($parse['query'], $params);
            unset($params["page"]);
            $url = $parse['path'] . '?' . http_build_query($params);
        }
        return $url;
    }

    function __get($args)
    {
        if ($args == "limit")
            return $this->limit;
        else
            return null;
    }

    private function start()
    {
        if ($this->total == 0)
            return 0;
        else
            return ($this->page - 1) * $this->listRows + 1;
    }

    private function end()
    {
        return min($this->page * $this->listRows, $this->total);
    }

    private function first()
    {
        $html = '';
//        if ($this->page == 1)
//            $html .= '';
//        else
            $html .= " <li> <a href='{$this->uri}&page=1'>{$this->config["first"]}</a></li>  ";

        return $html;
    }

    private function prev()
    {
        $html = '';
        if ($this->page == 1)
            $html .= '';
        else
            $html .= "<li><a href='{$this->uri}&page=" . ($this->page - 1) . "'>{$this->config["prev"]}</a> </li> ";

        return $html;
    }

    private function pageList()
    {
        $linkPage = "";
        $inum = floor($this->listNum / 2);
        for ($i = $inum; $i >= 1; $i--) {
            $page = $this->page - $i;
            if ($page < 1)
                continue;
            $linkPage .= "<li><a href='{$this->uri}&page={$page}'>{$page}</a></li> ";
        }
        $linkPage .= " <li><a style='background-color: #4F86B6'><font color='white'><b>{$this->page}</b></font></a></li> ";
        for ($i = 1; $i <= $inum; $i++) {
            $page = $this->page + $i;
            if ($page <= $this->pageNum)
                $linkPage .= " <li> <a href='{$this->uri}&page={$page}'>{$page}</a></li> ";
            else
                break;
        }
        return $linkPage;
    }

    private function next()
    {
        $html = '';
        if ($this->page == $this->pageNum)
            $html .= '';
        else
            $html .= " <li> <a href='{$this->uri}&page=" . ($this->page + 1) . "'>{$this->config["next"]}</a></li>  ";

        return $html;
    }

    private function last()
    {
        $html = '';
//        if ($this->page == $this->pageNum)
//            $html .= '';
//        else
            $html .= " <li> <a href='{$this->uri}&page=" . ($this->pageNum) . "'>{$this->config["last"]}</a></li> ";
        return $html;
    }

    private function goPage()
    {
        return '  <input type="text" onkeydown="javascript:if(event.keyCode==13){var page=(this.value>' . $this->pageNum . ')?' . $this->pageNum . ':this.value;location=\'' . $this->uri . '&page=\'+page+\'\'}" value="' . $this->page . '" style="width:25px"><input type="button" value="GO" onclick="javascript:var page=(this.previousSibling.value>' . $this->pageNum . ')?' . $this->pageNum . ':this.previousSibling.value;location=\'' . $this->uri . '&page=\'+page+\'\'">  ';
    }

    function fpage($display = array(0, 1, 2, 3, 4, 5, 6, 7, 8))
    {
        $html[0] = "  共有<b>{$this->total}</b>{$this->config["header"]}  ";
        $html[1] = "  每页显示<b>" . ($this->end() - $this->start() + 1) . "</b>条，本页<b>{$this->start()}-{$this->end()}</b>条  ";
        $html[2] = "  <b>{$this->page}/{$this->pageNum}</b>页  ";
        $html[3] = $this->first();
        $html[4] = $this->prev();
        $html[5] = $this->pageList();
        $html[6] = $this->next();
        $html[7] = $this->last();
        $html[8] = $this->goPage();
        $fpage = '';
        foreach ($display as $index) {
            $fpage .= $html[$index];
        }
        return $fpage;
    }
}